摘要 |
Processes are provided for starting up of anaerobic, deep tank fermentation systems used in the anaerobic bioconversion of hydrogen and carbon monoxide in a gaseous substrate stream to oxygenated organic compounds such as ethanol. In the processes injectors using a motive liquid are used to introduce gas substrate into the deep tank fermentation reactor where at least one of: (i) adjusting the gas to liquid flow ratio through an injector, (ii) changing the rate of liquid flow through an injector, and (iii) adjusting the carbon monoxide mole fraction in the gas feed by admixture with at least one other gas, wherein the mass transfer of carbon monoxide to an aqueous menstruum in the reactor is controlled to obtain the robust growth of the microorganism while maintaining the carbon monoxide concentration below that amount which is unduly adverse to the microorganism. In preferred aspects of the invention, recycled gas from the head space of the reactor is used to modulate the supply of carbon monoxide to the aqueous menstruum.
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